That looks good.
Really good, actually
I've made a few custom things myself when I can't find exactly what I'm looking for.
Some have been wood, some metal.
Your stand would be a really nice decorative piece for in the home when done with some hardwood as you are planning.
If you don't mind a little constructive criticism I think I would do a bit more sanding at the ends of the arcs of the cutouts in the sides.
Keep the meeting point(s) of the hole-saw holes and the jig-saw arcs less noticeable.
That's just a tradesman's critical-eye nitpick though.
I'm sure most folks would never notice.
If you plan to use this as an in-home decorative piece only, that will have no need to be disassembled, it might be nice if the hardwood version was fastened with glue and brads to eliminate the screws.
Make it look more like a piece of furniture.
A little filler for the brad holes before sanding and stain/finish.
Are you thinking walnut sides and ash rails?
Or vise versa?
Might be tricky finding a piece of hardwood wide enough for a side.
Maybe some walnut ply with an iron-on edging?
Might take a bit of work to apply inside the cutouts.
Unless perhaps you have an 18" thickness planer (or access to one) and were thinking of gluing strips to create a wide enough piece.
Whichever route you go, I look forward to seeing your pics.
Great project and nicely done.
I'm always open to constructive criticism.
This is what the meeting points look like up close, not perfect but I can live with it. I used a 3/4" Forstner bit to get things rounded since I knew a sharp meeting point wouldn't work and be barely accessible to sanding. I hate using jigsaws for the most part and that was my least favourite part of the project, that and getting the curves right, so after that was all done I used a spindle sander mounted in a drill, since I don't have an oscillating sander or a drill press to use. I had both sides clamped together to even things out and then took to the router and some finer sanding. It isn't the best but I know I'm ok with it and it will do the job. Some of it looks a little rougher in appearance due to the router burn but that will blend in with the stain, I've done it before and I like the look.
The hardwood version, if I ever get to it, I'd like to be glue and dowels or biscuits, both if needed. Two woods for contrast and different lines. The width will for sure be tricky but I'm sure I can come up with a creative solution, edge or lap joints, and I have a friend with a fully equipped wood shop that I would ask to use as he has much better equipment than I have in my garage. That may or may not happen, for now I can finally have all the guitars out in a tight space with quick access.